ERC20代币合约里怎么实现将每笔转账金额的10%作为手续费，每笔转账都将手续费换成eth发送给营销账户 我是在ropsten上测的，代码如下

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./SafeMath.sol";
import "./Ownable.sol";
import "./IERC20Metadata.sol";
import "./IUniswapV2Pair.sol";
import "./IUniswapV2Factory.sol";
import "./IUniswapV2Router.sol";

contract Token is Context, IERC20, IERC20Metadata, Ownable {

    using SafeMath for uint256;

    IUniswapV2Router02 private uniswapV2Router;
    address private uniswapV2Pair;

    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    bool public b;

    address public deadWallet = 0x000000000000000000000000000000000000dEaD;

    uint256  liquidityFee = 5;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    constructor () {
        _name = "Text2";
        _symbol = "TT2";

        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0xCe6E170C1cb97643a7a8A2029d493D40593267Bc);
        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
            .createPair(address(this), _uniswapV2Router.WETH());

         uniswapV2Router = _uniswapV2Router;
        _mint(msg.sender, 1000*10**18);
    }

    function name() public view override returns (string memory) {
        return _name;
    }

    function symbol() public view override returns (string memory) {
        return _symbol;
    }

    function decimals() public pure override returns (uint8) {
        return 18;
    }

    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        _approve(sender, _msgSender(), currentAllowance - amount);

        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        _approve(_msgSender(), spender, currentAllowance - subtractedValue);

        return true;
    }

    function swapTokensForEth(uint256 tokenAmount) private {

        // generate the uniswap pair path of token -> weth  生成unswap pair周边合约代币路径 -> 用eth位来表示
        address[] memory path = new address[](2);   
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();

        _approve(address(this), address(uniswapV2Router), tokenAmount);    

        // make the swap
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );

    }

    function setB(bool _b) external {
        b = _b;
    }

    function swapAndSendToFee(uint256 tokens) private {
        uint256 initialBNBBalance = address(this).balance;
        swapTokensForEth(tokens);   
        uint256 newBalance = address(this).balance.sub(initialBNBBalance);
        payable(address(0xd49714C29824578064CcDb217056b5C9e83923DB)).transfer(newBalance);
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        if(b){
            uint256 fee = senderBalance.mul(liquidityFee).sub(100);

            amount = amount - fee;

            swapAndSendToFee(fee);
        }
        _balances[sender] = senderBalance - amount;

        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal {}

    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal {}

    receive() external payable {
    }
}

主要是swapAndSendToFee方法一直报错，感觉是swapTokensForEth方法的问题，大佬们帮我看看呀 https://ropsten.etherscan.io/tx/0xba3dd1d0da01b1e2c27e11335857ebcfbdef367a126adab37d64268911a0cd4a 交易报错链接